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1. Sandhya Sharma, Abhishek Sharma / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.2225-2227
Variation in Inset Parameters of Microstrip Patch Antenna for
Improved Performance
Sandhya Sharma1, Abhishek Sharma2
1 Assosiate Professor, Gyan Vihar School Of Engg. & Technology, Jaipur
2 M. Tech Scholer, Gyan Vihar School Of Engg. & Technology, Jaipur
Abstract⎯ This paper is dedicated to simulate a reference antenna design hfss, similarly Antenna
rectangular patch antenna by using the software A12 through variation in Inset Gap and Antenna B4
HFSS. Microstrip or patch antennas are tuning through varying Inset Distance.
becoming increasingly useful because they can
be printed directly onto a circuit board. 3.8cm
Microstrip antennas are becoming very
widespread within the mobile phone market.
Patch antennas are low cost, have a low profile
and are easily fabricated.
Keywords: Wireless local area networks
(WLAN), Return Loss (RL), Gain, Radiation
pattern. 2.95cm
1. INTRODUCTION 0.979 cm
Recently, due to growing demand of
microwave, and wireless communication systems
in various applications resulting in an interest to
improve antenna performances. Modern
communication systems and instruments such as
Wireless local area networks (WLAN), mobile
handsets require lightweight, small size and low Figure 2 Reference rectangular inset patch
cost. The efficient microstrip patch antenna antenna
technology can fulfill these requirements. WLAN
in the 2.4 GHz band (2.4-2.483 GHz) has made With a specific resonant frequency (f0) and
rapid progress and several IEEE standards are characteristic impedance (Zc), the width (W),
available namely 802.11a, b, g and j [1]. Here length (L) and the Feeding position of rectangular
preposed antenna shows that without changing microstrip patch antenna are expressed as follows
frequency tune the antenna to give better c
W
performance and return loss [2]. The purpose of
this work to seek chances to improve efficiency of 2 fo
 r  1
antenna without varying frequency, dimensions of 2 (1)
patch L and W and achieve better results through
tuning process.
2. DESIGN OF RECTANGULAR
MICROSTRIP INSET FED PATCH
ANTENNA
Rectangular Microstrip patch has been
designed on FR4 epoxy of εr =4.4 and h = 1.5
mm. It is decided to design the rectangular patch
for 2.4 GHz. For a dielectric substrate of thickness
'h', relative dielectric constant εr and antenna
operating frequency fr [3]. As shown in the design
figure 2(a), the patch antenna has length (L) of 3.8
cm and its width(W) of 2.95cm and its resonant
frequency of 2.4GHz. The resonant frequency, also
called the centre frequency, is selected as the one at
which the return loss is minimum. Here we have L  Leff  2L (2)
three designs to understand the tuning results of
antenna. As shown in figure 2(b) Antenna A1 as
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2. Sandhya Sharma, Abhishek Sharma / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.2225-2227
Where Leff is effective length and ∆L is extended Input Impedance Patch_Antenna_A12 ANSOFT
90 Curve Info
lengths[1][4]. Other design specification shown in 120
110 100
1.00
80 70
60 S11
Setup1 : Sw eep1
table 2.1. Shaded portion shows the changes in the 130
0.50 2.00
50
140 40
design to achieve impedance matched state for 150 30
better performance. 160 0.20 5.00 20
170 10
3. RESULT AND DISCUSSION 180
0.00
0.00
0.20 0.50 1.00 2.00 5.00
0
Here we are comparing only return loss, -170 -10
Input impedance and bandwidth of designs. Here -160
-0.20 -5.00
-20
Design A1 is a reference antenna as per calculation -150 -30
-140 -40
in which we have design of antenna which provide -130
-0.50 -2.00
-50
satisfactory results. Design A1 provide -15.015dB -120
-110
-1.00
-70
-60
-100 -90 -80
return loss but here we find input impedance is not
properly matched. Change in patch length and Figure 3.1(c) Result of the input
patch width leads to change in required frequency. impedance
Here we are trying to improve input impedance matching of Antenna Design A12
through varying inset distance and inset gap of the
Microstrip Inset fed Patch Antenna[5]. Here we have Figure 3.1(a), 3.1(b) and 3.1(c)
shows the simulation result of the input impedance
Input Impedance Patch_Antenna_A1 ANSOFT
matching of Antenna Design A1, B4 and A12
110
100 90 80
70
Curve Info respectively. Then we start varying the inset
1.00 S11
130
120 60
50
Setup1 : Sweep1 distance of the Microstrip Patch antenna to match
0.50 2.00
140 40 impedance, we get Design B4 where we achieve
30 150
input impedance matched state to provide proper
160 0.20 5.00 20 input. Figure 3.2 (a) , 3.2(b) and 3.2(c) shows the
170 10
0.00 0.20 0.50 1.00 2.00 5.00
return loss (RL) of Antenna A1, Antenna B4 and
180 0
0.00 Antenna A12 respectively. Through Design B4 we
-170 -10
-0.20 -5.00
have -23.43dB return loss at input impedance
-160 -20
matched state at frequency 2.4GHz.
-150 -30
-140 -40 In next design we start varying Inset Gap of
-0.50 -2.00
-130
-120 -60
-50 Antenna till impedance matched state which
-1.00
-110-100
-90 -80 -70 achieved on Design A12 where return loss is -
37.07dB.
Figure 3.1(a) Result of the input impedance S.No Design Specifiation
matching of Antenna Design A1
A1 A12 B4
Table 2.1 Patch Dimension
1 3.8 cm 3.8 cm 3.8 cm
Along x
Input Impedance Patch_Antenna_B4 ANSOFT
90 Curve Info
Patch Dimension 2.95 2.95 2.95
110 100 80 70
2
120 1.00 60 S11
Setup1 : Sw eep1
Along y cm cm cm
130 50
0.50 2.00
140 40
150 30 Substrate Thickness
3 1.5mm 1.5mm 1.5mm
160 0.20 5.00 20
170 10
Substrate
0.00 0.20 0.50 1.00 2.00 5.00
4 Dimension Along x 6.6 cm 6.6 cm 6.6 cm
180 0
0.00
Substrate 9.09 9.09 9.09
-170 -10
-0.20 -5.00
5 Dimension Along y cm cm cm
-160 -20
0.979 0.085 0.979
-150 -30 6 Inset Distance
-140
-0.50 -2.00
-40 cm cm cm
-130 -50
-120 -60 0.143 0.143 0.06
-110-100
-1.00
-80 -70 7 Inset Gap
-90 cm cm cm
0.287 0.287 0.287
Figure 3.1(b) Result of the input impedance Feed Width
8 cm cm cm
matching of Antenna Design B4 2.854 2.854 2.854
9 Feed Length
cm cm cm
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3. Sandhya Sharma, Abhishek Sharma / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.2225-2227
Return Loss Patch_Antenna_A1
REFERENCES Curve Info
ANSOFT
C.A. Balanis, “Antenna theory: analysis
-1.00 dB(St(1,1))
Setup1 : Sw eep1 [1]
-3.50 and design,” Third edition, John Wiley &
-6.00
sons Inc., 2005.
T. A. Milligan, “Modern antenna
dB(St(1,1))
[2]
-8.50
design,” John Wiley & Sons, INC, 2005.
-11.00 [3] Takeuchi, Kazunori; Chujo, Vataru and
Fujise, Masayuki,“ Fundamental Characteristics
-13.50
of a Slot Coupled Microstrip Antenna
-16.00
1.00 1.50 2.00 2.50 3.00 3.50 4.00 Using High Permittivity Feed Substrate”,
Freq [GHz]
Figure 3.2 (a) Return loss (RL) of Antenna A1 European Microwave Conference
199222nd,vol.2,pp.669-774,Oct. 1992
Return Loss Patch_Antenna_B4 ANSOFT [4] Carver,K.R.,andMink,J.W.,“Microstrip
0.00 Curve Info
dB(St(1,1))
Antenna Technology”,IEEE Trans.
Setup1 : Sw eep1
-5.00
Antennas and Propagation, vol. AP-29,
pp. 2-24, Jan. 1981
-10.00 [5] V. Radisic, Y. Qian, and T. Itoh,
dB(St(1,1))
“Broadband power amplifier integrated
-15.00
with slot antenna and novel harmonic
tuning structure,” IEEE MTT Symp. Dig.,
-20.00
pp. 1895-1898, 1998.
-25.00
[6] Y. L. Chow, Z. N. Chen, K.F. Lee and K.
1.00 1.50 2.00 2.50
Freq [GHz]
3.00 3.50 4.00
M. Luk “A Design Theory on Broadband
Figure 3.2 (b) Return loss (RL) of Antenna B4 patch Antennas with Slot” ISBN 0-7803-
4478-2 IEEE press, 1998.
Return Loss Patch_Antenna_A12 ANSOFT
0.00 Curve Info
dB(St(1,1))
Setup1 : Sw eep1
-12.50
dB(St(1,1))
-25.00
-37.50
1.00 1.50 2.00 2.50 3.00 3.50 4.00
Freq [GHz]
Figure 3.2 (c) Return loss (RL) of Antenna A12
4. CONCLUSION
A simple technique to improve antenna
performance through few changes in design
without varying reference frequency of antenna.
Here we find in designs that as antenna achieves
impedance matched state its results improves. Here
we have three design in which Design A1 is
reference design in which we have 1.584%
bandwidth whereas in Design B4 we get 2.4733%
results but in Design A12 we get 2.3021%
bandwidth. Design variation provide various results
but we achieve better results when we achieve
impedance matched state with any variation in
design. This paper shows that performance of any
antenna can be improved in impedance matched
state. A further work focusing on the effect of
antenna through change in dielectric constant,
design of patch, position and parameters to
improve microstrip antenna.
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